Most photographs are produced by exposing a film to light and developing the film to produce either a negative or a positive. The negatives can be processed (printed) to produce a photographic print, which may be directly viewed. The positives on the other hand are typically mounted onto slide mounts. The slide mounts or slides are fed into a carousel type magazine or an inline canister type magazine slide projector for successive viewing.
In a slide projector, successive slides which are contained in a magazine or canister are individually sequenced between an illumination source and an optical device. The illumination source focuses light onto the slide. The optical device then projects the image of the slide onto a viewing surface, such as a projection screen.
Current carousel type magazine such as those manufactured by the Eastman Kodak Company under the tradename of Carousel or inline type projection systems, are capable of storing approximately 80 slide mounts at one time.